Brake Disc Design- Torque Acting On Wheel Stud Bolts

[cjh1990]

Homework Statement

I have currently been working on a group project designing a brake disc assembly. The current problem i am having is trying to workout the force acting on each wheel stud.

The frictional force of the brake pad is 3.2 KN with an efective radius of 105MM from the center of the disc
The 4 wheel studs concentric to the disc have a pcd of 65MM

What would be the force acting on each stud? i need to know this so i can further calculate the minimum bolt diameter. I will attach the work that my group mate has done so far however i doubt the initial calcualtions to find the force acting on each bolt is correct.

Homework Equations

the link to my current workings are as follows

http://i175.photobucket.com/albums/w154/christophercorsa/hpqscan0001.jpg

The Attempt at a Solution

 

[mender]

Looks like you're not thinking about the rotor being clamped between the hub and the wheel.

You'll need the thread pitch and the tightening torque on the nuts, plus the coefficient of friction between the rotor and the hub. That will give you the clamping force and the resulting resistance to shifting of the rotor.